1. Field of the Invention
This invention relates to improved smoking pipes, and more particularly to an improved smoking pipe having a bowl comprised of a lightweight Portland cement concrete, including Portland cement paste of high porosity (high water to cement ratio), and lightweight, porous aggregate materials.
2. Description of the Prior Art
The use of pipes for smoking dates back hundreds of years, and the qualities of good pipes are well known to all smokers. Perhaps the most important of these qualities is taste. A pipe must be sufficiently neutral so that the smoker will be able to taste the tobacco which he has chosen. This quality of proper taste is perhaps the most difficult quality to obtain when an inexpensive pipe is chosen.
Other qualities which good pipes must provide include a cool and dry smoke having an agreeable and mild taste and one which is absolutely free from biting and disagreeable effects. Also, the pipe bowl should not get excessively hot to the touch and the pipe itself should be light in weight, porous, and capable of absorbing the moisture and tars produced by the burning tobacco thereby preventing the formation of a wet soggy mass of tobacco in the bowl which results in difficult flammability of the tobacco and unpleasant taste.
Another quality that good pipes have is the quality of not requiring extensive "breaking in", that is, pre-smoking, before normal use. However, many pipes which taste good and are cool to the touch are expensive and difficult to make.
High quality pipes can be provided from bowls made of briar or meerschaum, as is known in the art. Briar is a root of a particular bush or tree, having a woody structure but being relatively hard, impervious, and resistant to burning. Meerschaum is a mineral substance, seprilite, which is imported from Asia Minor. This mineral is a fine, porous, clay-like material which is soft and light in weight, and does not impart a foreign taste or odor to burning tobacco.
Although high quality briar and meerschaum are excellent materials for smoking pipes, they are becoming scarce and increasingly expensive. Consequently, these materials have sometimes been used only as liners in pipes in order to reduce cost.
The prior art includes many attempts to provide good pipe substitutes for briar and meerschaum. However, these alternate materials have not found widespread acceptance, primarily due to taste considerations or considerations relative to the other qualities mentioned earlier. One alternative pipe bowl material that has been used is a hollowed cut corncob. Although this is cheap, it has many disadvantages, such as the disadvantage of contributing undesirable and disagreeable taste to the smoke. Also, corncob pipes develop a disagreeable taste after relatively short usage.
Other alternative pipe materials include cherry wood and hickory wood. However, pipes made from these materials have disagreeable tastes and are not popular for this reason. Still further alternative pipe materials include those having a thick plastic outer layer and an extremely thin layer of pyrolytic graphite which serves primarily as thermal insulation. Such pipes are very heavy, non-absorbent of moisture, and exhibit very poor taste.
U.S. Pat. No. 1,683,959 describes a pipe having an outer shell of wood or similar material and an inner liner of burnt clay and a cementitious mixture (a general term describing a binder material). This pipe was made to simulate clay pipes. It is generally heavy and does not last long. This pipe is made of fragile material and, most importantly, lends a harsh taste to the tobacco and smokes very hot because it is a good conductor of heat. Thus, it is basically a ceramic pipe of heavy weight, high heat conductivity, and poor taste. As will be more apparent, the pipes of the present invention are distinguished from this type of pipe in that they are comprised of a composite aggregate which is extremely porous and lightweight, and which does not adversely influence taste.
U.S. Pat. No. 204,774 describes pipes having carved pumice stone interiors with an outer coating which is applied in a plastic condition and then hardens. Examples of this outer coating include meerschaum chips, compositions of magnesia, plaster of paris, chalk, or other substances which can be applied in a plastic condition and then hardened. The disadvantage of these pipes is that any of the materials suggested lend terrible tastes to the smoking tobacco. Also, such materials as magnesia, plaster of paris, and chalk are brittle and disintegrate when subjected to heat or dropped.
U.S. Pat. No. 191,385 also describes a pumice-stone pipe which uses pulverized pumice stone mixed with some cementitious material. However, the patent points out that the porosity of the natural pumice would be destroyed if mixed with some cementitious material and therefore teaches away from this combination.
U.S. Pat. No. 1,368,371 describes pipes having an outer wood shell and an inner layer of Portland cement or plaster of paris, or a mixture of these. The disadvantages here are that both plaster of paris and Portland cement paste provide heavy pipes of poor porosity and low heat insulation. The use of a porous, lightweight aggregate with cement is essential, and is only taught in the present invention.
Other patents generally describing pipes which are alternatives to briar and meerschaum pipes include U.S. Pat. No. 379,585 and U.S. Pat. No. 3,695,276. The first of these describes a pipe having an outer bowl of a material such as wood, and an inner bowl of an absorbent material such as paper pulp. This pipe tends to get very hot and the inner lining does not last long. The second patent describes a pipe which is made of a chemical composition including poly (arylene sulfide). This material can be mixed with asbestos, paperbestos, or glass. The main disadvantage of this pipe is its poor taste when smoked.
U.S. Pat. No. 2,485,222 and 3,422,821 describe pipes having plastic layers on the outside of the bowl and meerschaum inner linings. As mentioned, these are attempts to obtain the good qualities of meerschaum but at lower cost. The resulting pipes are no better than commonly used briar pipes. U.S. Pat. No. 1,727,763 describes a smoking pipe having an inner bowl comprised of briar, etc. and an outer bowl of a resin which rigidly contacts the inner bowl. Again, this pipe still requires the use of more expensive materials and does not provide any significant advantages over conventional briar pipes.
In contrast with the prior art pipes mentioned, the present invention is a high quality pipe that is inexpensive and easy to fabricate. It is comprised of inert materials which will not adversely affect the tobacco taste and which will introduce no chemical impurities into the smoke. Also, this pipe has high porosity and is therefore very absorbent. Because of this, complicated structures for trapping moisture do not have to be utilized. In further contrast with the prior art, materials having very high porosity are held together by a cement which has approximately the same porosity and chemical composition so that the diffusion properties of the pipe are maintained. The porosity of the cement can be varied on a molecular scale while still maintaining the durability and lightness of the pipe.
Accordingly, it is a primary object of this invention to provide a pipe which has the qualities of a good, expensive pipe, but which is fabricated from readily available, inexpensive materials.
It is another object of this invention to provide inexpensive substitutes for briar and meerschaum pipes without sacrificing smoking quality.
It is a further object of this invention to provide a smoking pipe of unique composition which does not require extensive "breaking-in" (pre-smoking) before normal use, and which is inexpensive and yet of high quality.
It is yet another object of this invention to provide a pipe which can be cast in any shape or decorative form, at low cost, without the expensive machining or carving necessary with such materials as briar or meerschaum.
Another object of this invention is to provide a pipe material which can successfully be sheathed with a strong plastic material, applied at relatively high temperature (425.degree. F.), for strength and durability against the cracking, common in other pipe materials, caused by the buildup of carbon in the pipe bowl after extended smoking of the pipe.